Printing-frame.



No. 725,276. PATBNTBD APR-1 4, 190s.

G. A. MGMENIMBN.

PRINTING FRAME.

. APPLICATION FILED JUNE s, 1902.

No MoDBL.

@ya a upon the front side of the frame.

UNITED STATES PATENT OFFICE.

e'EoReE A. MCMENIMEN, .or CAMBRIDGE, MASSACHUSETTS.

PRINTING-FRAME.

SPECIFICATION forming part of Letters Patent No. 725,27 6, dated .April14, 1903.

application ne@ June 5. 1902. selifu 110.110.398. (No model.)

T all whom, t 777,603/ concern:

Be it known that I, GEORGE A. MCMENI- MEN, residing in the city ofCambridge, in the county of Middlesex and State of Massachusetts, haveinvented certain new and useful Improvements in Printing-Frames, ofwhich the following is a specification.

The object of this invention is to provide a and arrangement of partsset forth in the fol-v lowingr specication and particularly pointed outin the claims thereof.

Figure 1 is a perspective view of my im-n proved printing-frame with theback' clamped in position. Fig. 2 is a side elevation of the same withone of the clamp-rods elevated to release the pressure, upon the back ofthe frame and the other depressed in order to bring a pressure to bearupon said back. Fig. 3 is a transverse vertical section taken on line 33 of Fig. 2 looking toward the right in said figure. Fig. 4 is aperspective view in detail of one of the spring clamp-posts. Fig. 5 is aperspective view of the clamp-rod shown at the left of Fig. 1.

Like numerals refer to like parts throughout the several views of thedrawings.

In the drawings, is a printing-frame constructed in accordance with myinvention, which may be formed of wood or metal, but preferably ofmetal, consisting of four sides 11 11 and 12 12, each side beingprovided with a flange 13, projecting inwardly therefrom The negative 14rests upon the flange 13 and is held against said flange b va back-plate15, consisting, preferably, of two boards 16 16, connected together byhinges 17. The frame lO is provided with lugs 18, projecting laterallyoutward from opposite sides of said frame. The lower surfaces 19 of eachof the lugs 18 are cam-shaped, being formed upon a convex curve at 2Oand upon a concave curve at 2l, for the purpose hereinafter specied.

Upon each of the subdivisions 16 of the back-plate 15 is provided a pairof spring clamp-posts, said posts being located at opposite ends of saidsubdivisions 16 and adjacent to two of the lugs 18( Saidspringclampposts 22 each comprise a plat-e 23, provided with ears 36,through which screws are inserted to fasten said spring clamp-post tothe back-plate 15. is provided with a horizontal slot and is bentbackwardly from the plate 23 to form a horizontal spring-plate 24. Theother free end of said plate'extends upwardly therefrom through thehorizontal slot 25 and forms a guide-post 2.6, provided with a verticalslot 27.

A clamp-rod 28 is provided to clamp the back-plate 15 against thenegative 14. Said clamp-rod 28 extends across the back-plato 15 and ispreferably provided in the center with a bend forming a handle 29 and ateach end-with a right-angle bend 30, which when said rod is in the`position shown in Fig 1- viz., clamping the` back plate 15 to theframe-extends lengthwise of said frame adjacent to and upon the innerside of the guidepost 26. Thence said rod is bent at 31 to extend in adirection substantially parallel to the main body of said rod throughthe vertical slots 27 until it reaches a point outside and above thelugs 18, where it is bent downwardly at 32 and again inwardly at 33 toreach beneath said lugs 18 and to bear against One free end of saidplate 23 the cam-shaped surface 19. The rod is finally given anotherbend in a direction parallel to theside 11 of the frame at 37 to form abearing-surface upon the rod when said rod is in engagement with thecam-surface 19,although this latter bend is not essential to thepraetical working of the device. vThe two clamprods 28 28 are duplicatesof each other, but are placed upon the frame in reversed positions atopposite ends thereof.

The operation of the device hereinbefore specifically described is asfollows: The backplate 15 is placed in the frame 10, as shown in Figs. 1and 3, resting upon the negative 14. Eachof the clamp-rods is thenthrown downwardly from the position shown in Fig. 2 at the left to theposition shown in Fig. 1, with the portion 33 of each of said rodsengaging the cam-surface 19 upon the under side of the lugs 18. thedownward movement of said clamp-rods ICO During the rst part of the bentportions 33 move along the convex curve 20, drawing the clamp-rods 28downwardly in -the slots 27, and upon further rotation of saidclamp-rods said bent portions 33 arrive at the concave curve 21,forminga lock which holds the clamp-rods firmly in position until theyare disconnected from the lugs by rotating the rods in the oppositedirection froml that hereinbefore described. As the rods are forceddownwardly, as hereinbefore described, the portions 30 of said rods bearupon and depress the horizontal spring portions 24 of the spring clamp-posts 22, so that the back-plate I5 is held againstI the glassnegative with a spring pressure on alccountlof the springs 24 beinginterposed between said clamp-rods and the back-plate 15. It will thusbe seen that by a single downward: movement, involving a quarter-turn ofthe clamp-rod 28, each subdivision of the back-plate 15 is securelyclamped in position against the negative with a yielding pressure.

It will be understood that the sensitized paper upon which thephotographic or other reproduction isfto be printed is placed betweenthe glass 14E and the back-plate l5, as is well known to those skilledin this art.

It will be noted that the angular bent portions 30 of the clamp-rod 28serve a twofold purpose. Bearing against the inner faces ot' theguide-posts 26 prevents any lateral movement'of said-rod with relationto the backpIate-l5, and-when the clamp-rod 2S is depressed, as shown inFig. 1, the angular portions 30 bear--against the upper surfaces of thespringplates 24, forcing them downwardly as the bent ends 33 of saidclamp-rod passaroundthe curves 20andintothe concave locking-curve 2l.

Having thus described my invention, what Iclaim, and desire to secure byLetters Patent, is-

1. In a device of the character described, a frame, a back-platetherefor, lugs fast to and projecting laterally outward beyond oppositevertical sides of said frame, and a clamp-rod extending across said backand pivot-ed thereto, said clamp rod formed to engage said lugs andclamp said back-plate to said frame when a partial rotation is impartedtofsaid clamp-rod.

2. In a device of the character described, a frame, a back-platetherefor, lugs fast to and projecting laterally outward beyond oppositevertical sides of said frame, said lugs each provided with a cam-shapedsurface, and a clamp-rod extending across said backplate and pivotedthereto, said clamp-rod formed to engage said cam-surface and clamp saidback-plate to said frame when a partial rotation is imparted thereto.

3. In a device of the character described, a frame, a back-platetherefor, lugs fast to and projecting laterally outwardfrom oppositevertical sides of said frame, springs fast to said back-plate, and aclamp-rod extending across said back-plate and pivoted thereto, saidclamp-rod formed to engage said lugs and having angular bends therein toengage the upper faces of said springs.

4. In a device of the character described, a frame, a back-platethereforylugs fast to and projecting laterally outwardiuponopposite-vertical sides of said frame, clamp-posts fast tosaid'back-plate, each of said clampposts provided with a vertical slot,springs fast to said back-plate, and a clamp-rodextending across saidback-plate and through said slots, said clamp-rod formed to engage saidlugs and having angular bends therein to engage the upper faces of saidsprings.

5. In a device of the character described, a frame, a back therefor, anda spring clamppos't, said spring clamp-post comprising a plate fast tosaid back, one free end thereof provided with a horizontal slot and bentupwardly and backwardly to form a horizontal spring-plate, the otherfree end ef said plate extending upwardly therefrom, through saidhorizontal slot, and provided with a vertical slot.

6. In a device of the character described, a frame,`a back therefor,lugs projecting laterally outward upon opposite sides of said frame,spring clamp-posts, each comprising a plate fast to said back, one freeend of said plate provided with a horizontal slot and bent upwardly andbackwardly to form a horizontal spring-plate, the other free end of saidplate extending upwardly therefrom, through said horizontal slot, andprovided with a vertical slot; and a clamp-rod extending across saidback, through said vertical slots, formed to engage said lugs and havingangular bends therein to engage the inner faces of the vertical freeends of said plate and the upper faces of the horizontal free ends ofsaid plate.

In testimony whereof I have afiixed my signature in presence of twoWitnesses.

GEORGE A. MCMENIMEN. Witnesses:

I-I. L. HARRISON, MORRIS J. BROWN.

ICO

